KTM 50 SX – The Most Popular Kids Dirt Bike for Motocross

Ask dirt riders to point you to a bike that’s “ready to race,” and they’ll point you to a
KTM. These Austrian bikes have a long line of racing in their heritage. And the KTM 50
SX fits right in.

The mini dirt bike can be a good motocross race bike. It is known for delivering concrete results. It can go as fast as 45 miles per hour (72 km/h), is very adjustable, and has a light and sturdy race components. The tall seat height (26.9 inches) works for kids who are big for their age.

Though it gives smaller kids a slight advantage, it makes the 50cc KTM a bike that will
take a long time to outgrow — in skill and size. Parents choose this bike for kids between the ages of 4 to 10 who are eager to race. With the power reduction kit (sold separately), beginners can learn to ride on trails.

The investment up front is high for this KTM 50 cc dirt bike. At USD 4,399, it costs
more than rivals like the Honda CRF50, Yamaha PW50 and the 50 SX Mini (its smaller
version). But for the price, your kid gets a bike that handles well and stays competitive at the local track.

KTM 50 SX – Spain, Sportsminicycles Motocross (Image Courtesy: KTM by R. Schedl)

Top Features of the KTM 50SX

This MX bike has features for beginners and racers alike:

  • Single-speed automatic clutch
  • Adjustable air forks and rear shock
  • High-performing engine
  • Disc brakes

Whether in learning or racing, an automatic clutch saves shifting trouble for later. This
allows your kid to focus on control and handling. Paired with powerful disc brakes,
KTM’s engine gives its rider the best power and control.

The addition of adjustable air forks and rear shock also makes sure the KTM 50 keeps
up with growth spurts. You can adjust for an increase in rider weight to make the bike
handle consistently well.

2021 KTM 50SX Specs

For a spec-by-spec look into this 50cc dirt bike, check out the details below.

Engine & Transmission50SX
Engine49cc, 2-stroke, liquid-cooled, single-cylinder, reed-valve
TransmissionSingle-speed automatic
ClutchCentrifugal clutch
Final driveChain
Power reductionPower reduction kit
2021 KTM 50 SX Motocross Dirt Bike - front angle
2021 KTM 50 SX Motocross Dirt Bike (Image Courtesy: KTM)
Starter & Gas Capacity50 SX
Key ignitionNo
StarterKick starter
Fuel capacity0.6 US Gallon (2.27 Liters)
2021 KTM 50 SX Motocross Dirt Bike - right angle
2021 KTM 50 SX Motocross Dirt Bike (Image Courtesy: KTM)
Suspension, Brakes & TiresKTM 50
Suspension, frontInverted air forks, Adjustable
Suspension, rearSingle-shock, Adjustable
Brakes, frontDisk brake
Brakes, rearDisk brake
Tires, front6/100-12 36M TT
Tires, rear2.75-10 38J TT
KTM 50 SX Dirt Bike - Left side
2021 KTM 50 SX Motocross Dirt Bike (Image Courtesy: KTM)
Dimensions/
Weight
Inches/
Pounds
Millimeters/
Kilograms
Seat Height26.9 inches684 mm
Ground clearance9.9 inches252 mm
Weight91.5 pounds41.5 kg
Overall lengthNot specifiedNot specified
Overall widthNot specifiedNot specified
Overall heightNot specifiedNot specified
2021 KTM 50 SX Motocross Dirt Bike (Image Courtesy: KTM)
Price & Warranty50 SX
Price$4,399 (USD)
Warranty30 days limited warranty
Extended WarrantyN/A

The KTM 50SX Review

In this section, we’ll go into more detail about the general overview we covered so far.

“Ready to Race” Styling

KTM 50SX has bold and aggressive graphics. This gives it a natural competition bike
looks. The sharp lines of its larger brothers are present in this bike. And they do a good job of broadcasting the bike’s racing performance.

Combined with the tall seat, knobby tires, bold bodywork, and disc brakes fit right in at the starting gate of a race.

50SX Performance

The heart of the KTM 50 is its 2-stroke engine. It had a definite kick to it, but the power delivery is steady. The bike is also water-cooled, so you don’t have to worry about overheating parts. The frame is made of light and strong Chromoly steel. The material makes the bike stiff, which means more stability and better handling.

2017 KTM 50 SX – Spain, Sportsminicycles Kids Motocross (Image Courtesy: KTM by R. Schedl)

Safety

Racing dirt bikes don’t have as many safety features as beginner trail bikes. But that
doesn’t make the KTM SX 50 unsafe.

You can buy and install a power reduction kit for it, and that reduces the amount of
power the engine delivers. It makes the bike safe and secure for beginners. It doesn’t
mess with your child’s progress by making them fearful of the bike.

Convenience

The convenience of this bike comes from its adjustability. The front air forks and rear
shock can be adjusted with common tools like a wrench and an air pump. The bike also has a switch that you can push on before you kick-start the bike.

While a Kickstarter isn’t as convenient as an electric start button, it makes the bike
lighter as there’s no battery to carry. It also provides additional security and peace of
mind. Beginner 4 – 5 years old little ones can’t just hop on, start the bike and go on their own. Most of them would generally need you to help them start the bike.

Handling of the 50SX

Whether in the hands of a beginner or experienced rider, the KTM 50SX rides well. It
has great suspension that absorbs impact and rough terrain. The knobby tires give
riders confidence to tackle all kinds of dirt surfaces, from gravel trails to mud. The front and rear disc brakes make stopping easy. They have enough grab to stop the KTM’s lively engine without being too powerful.

Engineering from the 50SX Specs

It’s not surprising to know that most of the bike’s engineering is geared towards racing. The frame and handlebars are light and stiff to offer a youth rider more control and stability. The swingarm was redesigned to absorb more stress from racing. And the clutch can be detuned and adjusted to find the best power output.

2018 KTM 50 SX – Minneapolis Supercross (Image Courtesy: KTM by Simon Cudby)

Rival Brands of 50SX

2021 FeaturesKTM 50SX SpecsHonda CRF50 Specs
Seat height26.9 inches21.6 inches
Wet weight95 lbs110 lbs
Suspension travel3.8 inches (front)
2.8 inches (rear)
3.4 inches (front)
2.8 inches (rear)
StarterKick StartKick Start
Engine Type2-stroke4-stroke
Price$4,399 USD$1,599 USD

While the KTM 50 SX makes for a popular race bike, it has some competition from the
SX Mini, Cobra 50, Honda CRF50, and Yamaha PW50. We’ll go over the main
differences in this section.

Let’s start with the SX Mini. At 22 inches high, it has a lower seat than the 50 SX. But
that’s not the only thing. It has less suspension travel and a more mellow engine than
the SX, which is great for beginners but not for racing. The good thing about the Mini is it has an oil tank (no need to premix fuel).

KTM 50 SX vs Cobra 50

The debate of KTM 50 SX vs Cobra 50 centers around racing performance. Both bikes
are 2-strokes, and the Cobra has better suspension and slightly more power. But it also needs more maintenance. Some parents have also had issues with getting parts. The KTM is also a smaller and cooler-running bike.

KTM 50 SX vs CRF50

For KTM 50 SX vs CRF50, the difference is more about use. As a two-stroke racer, the
KTM has more engine power and better suspension. On the other hand, the Honda
costs around a third of the price require less maintenance, and is more beginner-
friendly. The KTM is the better choice if your kid has a real interest in racing.

KTM 50 SX vs Yamaha PW50

When it comes to KTM 50 SX vs Yamaha PW50, the differences are night and day.
Both bikes are two-strokes. But the KTM is a powerful racing machine, while the teeny-tiny Peewee 50 makes riding as simple and easy for a complete beginner. PW 50 is about 8 inches shorter making it ideal for 4 – 5-year-olds who may be shorter for their age.

Resale Value

What’s it like to put up this KTM 50cc dirt bike for sale? If you keep the bike well-
maintained, the response will be positive. This mini KTM enjoys a high resale value.
Kids who already race can use a KTM50 in good condition as a practice bike.

If you go by the trusty references from the Kelley Blue Book, you’ll see trade-in values from $1,620 to $2,420 for models within the last 5 years. Dealership listing prices for the same models range from $2,410 to $3,545.

2018 KTM 50 SX – Minneapolis Supercross (Image Courtesy: KTM by Simon Cudby)

Final Thoughts on KTM 50 SX

The KTM 50 SX is the go-to bike and brand for parents and their kids when it comes to racing. This makes the bike a regular sighting in the secondhand market and at
dealerships. If you’re buying used, make sure to spend more checking for good running condition.

Parts and accessories are usually available. There are plenty that you can source
directly from KTM Powerparts.

Ideal for tall kids and kids excited to race, the KTM 50 SX is a bike for both beginners
and skilled riders. It’s a lively 2-stroke that should last a few years with diligent
maintenance.

KTM 50 SX is the most versatile bike among 50cc dirt bikes. It’s ready for race on track and with power reduction kit and no gears to shift it can be a good beginner bike. It is one of our top picks for Best 50cc Dirt Bike.

If you don’t let the upkeep and the initial cost scare you, you can end up with a high-
performing motocross bike. Your kid may just win a few medals and trophies with it.


FAQs – Frequently Asked Questions on KTM 50 SX

Find the answers to the most common questions about this KTM 50 2 stroke below.

1. How much does a KTM 50 cost?

A new KTM 50 SX costs $4,399 USD.

2. How fast does a KTM 50 SX go?

The KTM’s fastest speed is 45 miles per hour (72 kph).

3. Is a KTM 50 a 2 stroke?

Yes, it’s a 2-stroke.

4. Is a KTM 50 automatic?

Yes, it’s an automatic transmission, so there is no gear to shift. This allows the rider to twist and go.

5. Does a KTM 50 have a clutch?

Yes, but it’s a built-in automatic clutch that you don’t have to worry about. In other
words, there is no clutch lever on the handlebar because of automatic transmission.

6. How much HP does a KTM 50 have?

KTM hasn’t revealed the max horsepower of the 50 SX, but we do know it’s more than
5.5hp, which the power the engine puts out with a power reduction kit installed.

7. How much does a 50cc dirt bike cost?

It depends on your choice. Beginner 50cc trail bikes start at $1,500, while 50cc racing
bikes start at around $3,800.